Trimming mechanism for sewing-machines.



APPLICATION FILED FEB. 5 I9I4- Patented Jan.15,1918.

5 SHEETS-SHEET I- J. R. MOFFATT. TRIMMING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED FEB. 5,1914- 1 53fi65u Patented Jan.15,1918.

5 SHEETS-SHEET 2- I. R. MOFFATT.

TRIMMING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED FEB. 5. 1914.

1].,g53,865v Patented Jan. 15, 1918.

5 SHEETS-SHEET 3 J. R. MOFFATI. TRIMMING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED FEB. 5,1914- 153 65u Patented Jan.15,1918.

5 SHEETS-SHEET 4- J. R. MOFFATT. TRIMMING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED FEB. 5, 19M. 1 258 865v Patented Jan.15,191.8.

5 SHEETS-SHEET 5.

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JAMES It. MOFFAT'I, OF CHICAGO, ILLINOIS, ASSIGNOR T0 UNION SPECIALMACHINE J COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION 015 ILLINOIS.

TRIMMING MECHANISM FOR SEWING-MACHINES.

messes.

Specification of Letters Patent.

Patented Jan. 115, 1918.

Application filed February 5, 1914. Serial No. 81.63%.

To all whom it may concern:

- citizen of the United States, residing at Chicago, in the county ofCook, State of Illinois, have invented certain new and usefulImprovements in Trimming Mechanism for Sewing-Machines, of which thefollowing is a description, reference being had to the accompanyingdrawing and to the figures of reference marked thereon.

The invention relates to new and useful improvements in trimmingmechanisms for sewing machines, and more particularly to a trimmingmechanism wherein the trimming members operate in substantially ahorizontal plane in advance of a cross-stitching mechanism for trimmingthe edges of fabric, which edges are abutted and joined bycrossstitching.

An object of the invention is to provide a trimming mechanism whereinthe movable trimming blade is postively reciprocated back and forth andis held in proper contact with its cooperating member.

A further object of the invention is to provide a presser foot withmechanism for supporting the trimming devices, and with a deflectorwhich is fixed to the presser foot for deflecting the trimmed-ofl' stripaway from the stitching mechanism.

lhese and other objects will in part be obvious, and will in part behereinafter more fully disclosed.

In the drawings, which show by way of illustration one embodiment of theinvent1on,

Figure 1 is a side elevation of a sewing machine embodying my invention;

Fig. 2 is a vew partly in section and partly in plan, showing thetrimming mechanism,

the work support and presser foot;

Fig. 3'is an enlarged detail view, showing partly in section and partlyin plan the trimming mechanism and presser foot with the trimming bladeretracted;

Fig. d is a similar View, showing the trimmer blade in its forwardposition;

Fig. 5 is an enlarged perspective view, showing the presser foot, thetrimming mechanism and the forward end of the work support;

I Fig. 6 IS a detail in cross section, showing the fabric as it is bentprior to entering the presser foot;

Fig. 7 is a transverse sectional view through the presser foot and thetrimming mechanism;

Fig. 8 is a transverse sectional view at the stitching point;

Fig. 9 is a perspective view, showing the presser foot, the trimmingmembers and clamping devices therefor, the parts being separated to showthe structure;

Fig. 10 is an enlarged sectional View thit'iough the presser foot at theneedle slot; an 1 v Fig. 11 is a detail in perspective showing more orless diagrammatically the fabric, the trimming blade, the trimmed-0dstrip and the joined abutted edges.

The trimming mechanism embodying my improvement is of the type whereinthe trimming blades pperate in a horizontal plane in advance ofcross-stitching mechanism, and includes devices for positivelyreciprocating the trimming blade in both directions; devices for holdingthe trimming blade so as to prevent lateral deflection duri112 thetrimming action devices fixed to the presser foot and extending from oneside of the needle to the other for deflecting the trimmed-off strip.

Referring more in detail to the drawings, I have shown the invention asapplied to a side wheel feed-up-the-arm machine, conslsting of asupporting base or standard carrymg an overhanging arm 2, on which 1smounted a needle gate 3. A needle bar l reciprocates in the needle gate.This needle bar is reciprocated by the needle lever 5, which is pivotedat 6 to the overhanging arm.

A link 7 joins the needle lever to the needle bar. The needle leverextension d 15 connected to a link 9 which codperates with an eccentricon the main shaft 10, which 18 actuated by the usual belt wheel 11.

A needle 12 is mounted in the needle bar and the needle gate 3 isvibrated by the usual I mechanism for causing said needle 12 to enterthe fabric first at one side of the center line of scam and then at theother side thereof. A cylindrical arm or work support 13 is carried bythe standard 1, and pro ects underneath the overhanging armB. A feed dog14': is so disposed and operated as to feed the material up the arm 13.A looper A mounted in the work support coiiperates with the needle. Thislooper is of the usual type and the looper thread is formed into loopswhich not only lock the needle loops but extend across the center lineof the seam and join the needle loops on opposite sides thereof. Theneedle and looper constitute a crossstitching mechanism which joins theabutting edges of the fabric.

The above parts are of the usual construction, and further descriptionthereof will not be necessary.

A presser foot 15 cooperates with the work support in holding the fabricon the feed dog 14. This presser foot 15 has a shank 16 which is securedto the lower end of the presser bar 17. Said shank also has a laterallyprojecting arm 18 which carries a guide bar 19 which extends throughsuitable bearings in the overhanging arm and prevents the presser footfrom turning about the axis of the bar 17. The presser foot is slottedat 20. This slot extends from the forward end of the presser footcentrally thereof into the presser foot. and the side walls of the slotare tapered outwardly.

and joined, or forms a fold in the fabric when a section is to be cutfrom the same and the edges afterward joined.

The needle ,12 passes through a needle opening 22 formed in acylindrical boss 23 carried by the presser foot 15. The slot 20 leads tothe front face of the boss 23. The upper face of the presser foot isformed with an annular recess 24, the boss 23 forming the central wallof said recess. A stationary trimmer blade 25 is formed so as to fitsaid annular recess 24.

In other words, this stationary trimmer blade 25 is annular in shapehaving a central opening 26, which fits the boss 23. A section isremoved from the blade, so as to form a cutting edge 28. This stationaryblade is placed in the recess 24, and is held therein by a clamping arm29, which carries screws 30 adapted to press against the blade, asclearly shown in Fig. 10 of the drawings. This clamping arm is recessedas shown in Fig. to allow proper clearance in the descent; of the needlebar. A clamping screw 31 clamps the arm 29 to the presser foot, andcauses the screws 30 to press against the blade to hold it firmly in therecess 24. ll do not make claim to the special construction ofstationary trimmer blade parts, as that is not my invention. V

A movable cutting blade 32 is mounted so as to reciprocate in asubstantially horizontal plane. The presser foot is recessed, as at 33,to form a guideway for this. movable blade 32.

A bridge plate 34 spans the guideway 33 and 1s secured to the presserfoot by suitable screws. This bridge plate has a forwardly projectingarm 35, which bears against the blade at a point adjacent the slot 20,that is, a point adjacent the trimming line, and holds the blade inproper cooperative relation to the stationary trimming member 25.

The movable blade 32 is mounted in an arm 36 which is in the form of arock lever supported by a shaft 37. The other end of the rock lever 38carries a ball stud 39, to which is pivotally attached a link 49. Theshank of the presser foot 16 has a rearwardly projecting arm 41 which isslotted to receive the rock lever, and the shaft 37 carried by this armforms a pivotal support for the rock lever. The arm is provided with anextended bearing 42, so as to prevent the rock lever from tilting duringthe oscillations thereof. The arm 41 has a tongue 41 fitting in a groovein the extension 16 of the presser foot shank 16. The arm 41 is securedto the extension 16 by a screw 43, which passes through an elongatedslot 42' in the arm.

It will be noticed that by this arrangement, the arm or bracket 41 maybe vertically adjusted, by which the knife-carrying arm may be raisedand lowered, to accommodate varying thicknesses of knives.

A hardened block 43 carried by the arm 18, bears against the arm 36carrying the cutting blade, and also tends to hold said cutting blade inproper cooperative relation to the stationary cutting blade, giving afirm support for the arm 38, and, therefore, the movable knife. Thisblock is adjustable up and down on the presser foot shank by means of ascrew and elongated slot arrangement, as shown at 43'. In assemblingthese parts, the stationary knife is first secured in moved up, due tothe shearing action. The

arm 38 is disposed about three-eighths of an inch below the forked arm18, which allows for the vertical movement of said arm 38.

A stationary deflector 44 is attached to the presser foot by suitablescrews 45 and 46. This deflector is L-shaped. One part of the deflectorextends'substantially parallel with the slot 20 over the trimming blade,while the other member extends across the slot from one side of theneedle to the other side of the needle, and serves to deflect thetrimmed-ofi strip away from the stitching mechanism.

The itman is pivoted to a second rock lever 4? which is fulcrumed on abracket 48 secured ,to the standard 1; The lower arm of the rock lever47 is slotted, as at 49, and a ball stud 50 is adjustably secured insaid slot. The other arm of the rock lever 47 is pivotally connected toa link 51, which in turn is connected to a ball stud 52 on the needlelever extension 8. As the needle lever oscillates, the rock lever 47will be oscillated and through the link 40 will oscillate the cuttingblade 32. The parts are so timed and constructed that this cuttingbladeis positively moved back and forth and in timed relation to the needle,so that the cutting blade will be out of contact with the fabric whilethe needle is raised and during the forward feed of the fabric. The link40 is of such length that the presser foot may be raised and loweredwithout interfering with the actuations of the cutting blade.

In the operation of my device, the fabric (indicated at F in Figs. 6,7,8 and 11,) is fed to the machine and the deflector 21 forms a fold inthe fabric, so that as the fabric enters the slot in the presser foot,it will be in substantially vertical position, as indicated in Fig. 7The trimmer blade trims ofl the portion of the fabric extending abovethe blade, after which the trimmed edges are abutted and are joined bythe cross threads indicated at T in Fig. 8. The trimmed-off strip S isdeflected by the deflector 44 to one side of the stitching mechanism.

'By increasing or decreasing the fold formed in the fabric, (that is,the amount of fabric which is cut from the piece,) tubular articles maybe shaped and the trimmed edges joined. It will also be understoodthattwo separate sections may be be fed to the machine, and thedeflector 21 will raise the edges so they will be substantially verticaland in position for action by the trimming mechanism.

It is obvious that minor changes in the details of construction may bemade, without departing from the spirit of the inventionas set forth inthe appended claims.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent, is:

1. A sewing machine including in combination, a presser foot having arecess in its upper face forming a central boss provided with a needleopening, a trimming blade, means for holding the blade in said recess,said presser foot having a slot in its forward end extending to saidboss, a movable trim-- ming blade cooperating with the blade car.- riedby the presser foot, said presser foot having means for supporting themovable blade, whereby the same may be adjusted vertically, and adeflector carried by the presser foot and extending across said guidingslot for deflecting the trimmed ofl strip.

2. A sewing machine including in combitrimming mechanism carried by saidpresser foot and including a trimming blade mov-- ing in a substantiallyhorizontal plane, a rock lever pivotally supported by the presser footand carrying said trimming blade, a link connected to saidrock lever foroscillating the same, and means for connecting said link to said needlelever.

3. A sewing machine including in combination, a needle, a needle lever,means for oscillating the needle lever, a presser foot, a trimmingmechanism carried by said presser foot and including a trimming blademoving in a substantially horizontal plane, a rock lever pivotallysupported by the presser foot and carrying said trimming blade, a linkconnected to said rock lever for oscillating the same, a second rocklever mounted on the machine frame and having an adjustable connectionwith said link, and means for oscillating said second rock lever fromthe needle lever.

4. A sewing machine including in combiration, a presser foot having anextension, a trimming mechanism including a trimming blade moving in asubstantially horizontal plane, a vertically adjustable arm fixed onsaid extension, a lever carried by said arm and supporting said movableblade, and means for oscillating said lever.

5. A sewing machine including in combination, a presser foot having anextension, a trimming mechanism including a trimming blade moving in ahorizontal plane, an arm adjustably supported by said extension, a rocklever mounted on said arm and carrying said movable blade, a shaftsupporting said rock lever, said arm having an extended bearing for saidshaft for holding said rock lever from tilting on its pivotal axis.

6. A sewing machine including in combination, a presser foot having anextension, a trimming mechanism including a trimming blade moving in ahorizontal plane, an arm adjustably supported by said extension, a rocklever mounted on said arm and carrying said movable blade, a shaftsupporting said rock lever, said arm having an extended bearing for saidshaft for holding said rock lever from tilting on its pivotal axis, aneedle, a needle lever for reciprocatblade moving in a horizontal plane,an arm adjustably supported by said extension, a rock lever mounted onsaid arm and carrying said movable blade, a shaft supporting said rocklever, said arm having an extend ed bearing for said shaft for holdingsaid rock lever from tilting on its pivotal axis, and an adjustableblock carried by the presser foot and bearing on said rock leveradjacent the trimming blade. 8. A sewing maclnne lncluding 1n combnation, a presser foot, a stationary trimming member carried thereby,said presser foot having a recess formed therein for a trimming blademoving in a horizontal plane, an arm carried by the presser foot andbearing on said movable blade adjacent the trimming line for holdingsaid blade in proper cooperation with the stationary trimming 7 member.

' masses lation with said stationary trimming memher. 1

In testimony whereof, I aflix my signature in the presence of twowitnesses.

JAMES R. MOFFA'IT. Witnesses:

A. C. ABEL, 7 A. B. Cno'rmnn.

